[Eslam Hashem]

Dear Alhasan,

Unfortunately i deals with rotating blades and rotating zone should be considered in my study and i never found any thing a bout ffowcs williams and hawkings formula in openfoam. i don't know what should i do. if i didn't find any thing about fw-h in openfoam my study will stop.

please, can you suggest how i can solve this problem

[Alhasan]

Hi Eslam,

Search hard if some one has FW-H model written for openFOAM, its been there out too long both FW-H and OpenFOAM so some one should have written it at some point ?

If it is not necessary you have to use OpenFOAM, FW-H model is available in Fluent !!!

If not comes the complicated part where you have to write you own C++ codes for FW-H

you can start this by understanding the Curle's Equation and see how the model is written in OpenFOAM that is provided above, then you can try to understand FW-H equations and write your own.

- in my point of view writing a FW-H code for openFOAM and validation can be a BEng Dissertation by itself.

Best of Luck
Hasan K.J

[Eslam Hashem]

Hi Alhasan,

thank you my friend, i will work hardly to implement this analogy in openfoam. any time if you found any thing about this topic, i will be grateful for informing me.

Best regards,
Eslam H. Mohamed

[skeptik]

Originally Posted by Eslam Hashem

Hello skeptik,
I want ask for noise utility in openfoam, when i use it , i will need to use any other functionobject such as 'curlefunctionObject' or not. in other words, can noise utility be an alternative approach than acoustic analogy.

i will be grateful if you answer my questions

I have not understood your questions.

[Eslam Hashem]

i want to ask for how to implement an acoustic analogy in openfoam. my study focus on noise emitted from wind turbine and as we know, there is no acoustic model in openfoam. any one know how to do this especially using ffowcs williams and hawkings formula.

[Sethu]

Originally Posted by skeptik

1. Something is released. You can look for it here

Complex online post-processing:
How to implement simple acoustic analogy in OpenFOAM
(Sergei Strizhak, Matvey Kraposhin)

2. I know nothing about acoustics in Fluent or CFX except that using it you can get also wrong results.

Dear Ilya,

Thanks for sharing the code.

With the help of the notes given I could able to compile only the libraries (dynamically using wmake libso) but when I tried to link the main solver "libAcoustics" I am getting the following error.

In file included from /apps/OpenFOAM/OpenFOAM-2.2.2/src/OpenFOAM/lnInclude/OutputFilterFunctionObject.H:232:0,
from Curle/CurleFunctionObject.H:40,
from Curle/CurleFunctionObject.C:26:
/apps/OpenFOAM/OpenFOAM-2.2.2/src/OpenFOAM/lnInclude/OutputFilterFunctionObject.C: In member function ‘bool Foam::OutputFilterFunctionObject<OutputFilter>::ti meSet() [with OutputFilter = Foam::Curle]’:
Curle/CurleFunctionObject.C:40:1: instantiated from here
/apps/OpenFOAM/OpenFOAM-2.2.2/src/OpenFOAM/lnInclude/OutputFilterFunctionObject.C:219:9: error: ‘class Foam::Curle’ has no member named ‘timeSet’
make: *** [Make/linux64Gcc45DPOpt/CurleFunctionObject.o] Error 1
make: *** Waiting for unfinished jobs....

It would be nice if you could help me out to implement the solver properly..

Regards,

Sethu

[elvis]

Hi,
I saw that Professor Jasak made a OF-Summerschool anouncement
Adam Azenic: numerical simulation of the acoustic response in the edge tone simulation. Presenting a full non-linear acoustics solver
https://twitter.com/hrvoje_jasak/sta...93641565782017

[skeptik]

Originally Posted by Sethu

Dear Ilya,

Thanks for sharing the code.

With the help of the notes given I could able to compile only the libraries (dynamically using wmake libso) but when I tried to link the main solver "libAcoustics" I am getting the following error.

In file included from /apps/OpenFOAM/OpenFOAM-2.2.2/src/OpenFOAM/lnInclude/OutputFilterFunctionObject.H:232:0,
from Curle/CurleFunctionObject.H:40,
from Curle/CurleFunctionObject.C:26:
/apps/OpenFOAM/OpenFOAM-2.2.2/src/OpenFOAM/lnInclude/OutputFilterFunctionObject.C: In member function ‘bool Foam::OutputFilterFunctionObject<OutputFilter>::ti meSet() [with OutputFilter = Foam::Curle]’:
Curle/CurleFunctionObject.C:40:1: instantiated from here
/apps/OpenFOAM/OpenFOAM-2.2.2/src/OpenFOAM/lnInclude/OutputFilterFunctionObject.C:219:9: error: ‘class Foam::Curle’ has no member named ‘timeSet’
make: *** [Make/linux64Gcc45DPOpt/CurleFunctionObject.o] Error 1
make: *** Waiting for unfinished jobs....

It would be nice if you could help me out to implement the solver properly..

Regards,

Sethu

Did you try OF 2.1?

Although it was mentioned in libAcou documentation that it was developed for OF 2.1 and later, i'd suppose to compile it for OF 2.1

[Sethu]

Dear Ilya.,

Yes, it did work well for OF 2.1.0. I could able to compile all the solver codes and libraries in it. I also notice that "OutputFilterFunctionObject.C" file in OF 2.2.2 has got significant changes in it while revision. I dont know how to resolve this issue. But, I will proceed now with OF 2.1.0 to solve the test cases and some of my trail cases.

Thanks for your help. If you have any further updates on this solver, do let us know.

Regards,

Sethu

[bjornthe]

did you not add in Curle/Curle.C
"
void Foam::Curle::timeSet()
{
// Do nothing - only valid on execute
}
"

and in Curle/Curle.H
"
//- set time
virtual void timeSet();
"
It compiles on openfoam 2.2.0 then

[DAPHNE]

Originally Posted by skeptik

1. Something is released. You can look for it here

Complex online post-processing:
How to implement simple acoustic analogy in OpenFOAM
(Sergei Strizhak, Matvey Kraposhin)

2. I know nothing about acoustics in Fluent or CFX except that using it you can get also wrong results.

Dear Ilya and all,

Thank you so much for sharing the information.
From the presentation material ( OFW-Seoul-Kraposhin-AcousticTrack-5 pdf) given for Curle implementation discussed in slide 9 the expression used for
acoustic pressure is p'= 1/4IIc0_ * x/r^2 *[ (df/dt) + c0 f/r].

But in the Curle .C at line 288
scalar coeff1 = 1. / 4. / Foam::constant::mathematical:: pi / c0_ / c0_ ;

forAll (observers_, iObs)
{
SoundObserver& obs = observers_[iObs];
vector l = obs.position() - c_;
scalar r = mag(l);
scalar oap = l & (dFdT + c0_ * F / r) * coeff1 / r /r;
if (dRef_ > 0.0)
{
oap /= dRef_;
}
obs.apressure(oap);
}

}
}
It is clear that oap is the expression to find the p' value. But in the expression for oap, at the denominator we have c0_^2 , which is computed from the coeff1 expression. Is there any approximation made?Could you please explain is there any approximation like nearfield or farfield behind this approximation?

Thanks in advance.

[Delcraft]

Hello,

Unfortunately, the code shared by skeptic can't be downloaded anymore.

Originally Posted by skeptik

1. Something is released. You can look for it here

Complex online post-processing:
How to implement simple acoustic analogy in OpenFOAM
(Sergei Strizhak, Matvey Kraposhin)

Could anyone (including skeptic) share it again? Thanks in advance.

Best Regards,

Delcraft

[wyldckat]

Quick answer:

• Current website location: http://openfoam-extend.sourceforge.n...l?Main=2&sub=1
• File in question: http://sourceforge.net/projects/open...n.tar/download

edit: Links for all of these workshops: http://openfoamwiki.net/index.php/Ha...FOAM-Workshops

[Delcraft]

Thank you! That's exactly what I want.

Delcraft

[Alhasan]

Hey @Eslam Hashem
How did your project go, did you implement the FW-H model in OpenFOAM yet or did you find any one else who has implimented any other acoustic anology other than Curles provided by @Ilya in OpenFOAM

Regards,

Hasan K.J

[skeptik]

Hey all.

You can find updated libAcoustics with Curle analogue for OpenFOAM 2.3.0 through following link.

https://unihub.ru/resources/625

Thanks.

[Alhasan]

Thanks a lot for sharing this,

Eagerly waiting for the F-WH for openfoam if any updates please share with us,

Kind Regards,
Hasan K.J

[a_habib]

thanks for the updates but I have a problem
How I can compile it, it seems to be precompiled because ther is (lnInclude) folder and (deb) files.
any one can help me to compile it
thanks in advance

[a_habib]

Please. any one can help me compiling this library

[wyldckat]

Originally Posted by a_habib

Please. any one can help me compiling this library

Quick answer:

1. Make sure you're using OpenFOAM 2.3. For example:
   

   icoFoam -help

   Gives me this at the end:
   

   Using: OpenFOAM-2.3.x (see www.OpenFOAM.org)
   Build: 2.3.x-fdfc12484890

2. Download the ZIP file from the link in post #36.
3. Run as normal user the following commands:
   

   mkdir -p $FOAM_RUN
   cd $FOAM_RUN
   cd ..
   unzip ~/Downloads/libAcoustics.zip

   Note: Adjust the path "~/Downloads/libAcoustics.zip" to your needs.
4. Then run:
   

   cd libAcoustics-2.3
   ./cleanLib.sh
   ./makeLib.sh

5. If all goes well, the last line shown on screen should be something like this:
   

   '/home/ofuser/OpenFOAM/ofuser-2.3.x/platforms/linux64GccDPOpt/lib/libAcoustics.so' is up to date.